A gas cracker is any device that splits the
molecule
A molecule is a group of two or more atoms that are held together by Force, attractive forces known as chemical bonds; depending on context, the term may or may not include ions that satisfy this criterion. In quantum physics, organic chemi ...
s in a
gas
Gas is a state of matter that has neither a fixed volume nor a fixed shape and is a compressible fluid. A ''pure gas'' is made up of individual atoms (e.g. a noble gas like neon) or molecules of either a single type of atom ( elements such as ...
or
liquid
Liquid is a state of matter with a definite volume but no fixed shape. Liquids adapt to the shape of their container and are nearly incompressible, maintaining their volume even under pressure. The density of a liquid is usually close to th ...
, usually by
electrolysis
In chemistry and manufacturing, electrolysis is a technique that uses Direct current, direct electric current (DC) to drive an otherwise non-spontaneous chemical reaction. Electrolysis is commercially important as a stage in the separation of c ...
, into
atom
Atoms are the basic particles of the chemical elements. An atom consists of a atomic nucleus, nucleus of protons and generally neutrons, surrounded by an electromagnetically bound swarm of electrons. The chemical elements are distinguished fr ...
s. The end product is usually a gas. A
hydrocracker
In petrochemistry, petroleum geology and organic chemistry, cracking is the process whereby complex organic molecules such as kerogens or long-chain hydrocarbons are broken down into simpler molecules such as light hydrocarbons, by the breaking ...
is an example of a gas cracker. In nature, molecules are split often, such as in food digestion and microbial
digestion
Digestion is the breakdown of large insoluble food compounds into small water-soluble components so that they can be absorbed into the blood plasma. In certain organisms, these smaller substances are absorbed through the small intestine into th ...
activity. A gas cracker device splits the molecule at a rate much greater than that normally found in nature. In science and industry, gas crackers are used to separate two or more elements in a molecule. For example, liquid
water
Water is an inorganic compound with the chemical formula . It is a transparent, tasteless, odorless, and Color of water, nearly colorless chemical substance. It is the main constituent of Earth's hydrosphere and the fluids of all known liv ...
, or , is separated into hydrogen and oxygen gases. This is not to be confused with the splitting of the
nucleus
Nucleus (: nuclei) is a Latin word for the seed inside a fruit. It most often refers to:
*Atomic nucleus, the very dense central region of an atom
*Cell nucleus, a central organelle of a eukaryotic cell, containing most of the cell's DNA
Nucleu ...
(nuclear power).
Gas cracker
Petrochemicals are usually manufactured in large scale from petroleum feed stocks using
fluid catalytic cracking
Fluid catalytic cracking (FCC) is the conversion process used in petroleum refineries to convert the high-boiling point, high-molecular weight hydrocarbon fractions of petroleum (crude oils) into gasoline, alkene gases, and other petroleum produc ...
. Naphtha, natural gas, refinery off-gas and gas from cokers and thermal crackers are good sources. Thus natural gas is one of the most wanted feed stocks for petrochemicals production. The thermal cracking of natural gas proceeds at very high temperature resulting in olefins (Mostly ethylene/propylene). The temperature in a
gas cracker exceeds 1000°C. For ultimate decomposition of gas into elements more than 1500 °C is required. Thus,
acetylene
Acetylene (Chemical nomenclature, systematic name: ethyne) is a chemical compound with the formula and structure . It is a hydrocarbon and the simplest alkyne. This colorless gas is widely used as a fuel and a chemical building block. It is u ...
/
carbon black
Carbon black (with subtypes acetylene black, channel black, furnace black, lamp black and thermal black) is a material produced by the incomplete combustion of coal tar, vegetable matter, or petroleum products, including fuel oil, fluid cataly ...
production encounters such high temperatures. Usually
oxy-combustion methods are used for attaining such high temperatures.
BASF burners/Kellog burners are available in the market.
Other methods
Further
electro cracking or
plasma cracking methods are also available.
References
See also
*
Plasma polymerization
Plasma polymerization (or glow discharge polymerization) uses plasma sources to generate a gas discharge that provides energy to activate or fragmentation (chemistry), fragment gaseous or liquid monomer, often containing a vinyl group, in order to ...
*
Pyrolysis
Pyrolysis is a process involving the Bond cleavage, separation of covalent bonds in organic matter by thermal decomposition within an Chemically inert, inert environment without oxygen. Etymology
The word ''pyrolysis'' is coined from the Gree ...
*
Gas-phase ion chemistry
Gas phase ion chemistry is a field of science encompassed within both chemistry and physics. It is the science that studies ions and molecules in the gas phase, most often enabled by some form of mass spectrometry. By far the most important applic ...
Sources
* Fahad H. Falqi, 2009, The Miracle of Petrochemicals: Olefins Industry : an In-depth Look at Steam Crackers.
* Herman F. Mark, 2013, Encyclopedia of Polymer Science and Technology, Concise.
* William L. Leffler, 2014, Natural Gas Liquids: A Nontechnical Guide.
Citations
Electrolysis
cracker
Cracker, crackers or The Crackers may refer to:
Animals
* ''Hamadryas'' (butterfly), or crackers, a genus of brush-footed butterflies
* '' Sparodon'', a monotypic genus whose species is sometimes known as "Cracker"
Arts and entertainment Films ...
{{electrochem-stub